CN114901329B

CN114901329B - Syringe appliance

Info

Publication number: CN114901329B
Application number: CN202080088985.1A
Authority: CN
Inventors: 罗西·赫特; 马修·约翰·多布森
Original assignee: Owen Mumford Ltd
Current assignee: Owen Mumford Ltd
Priority date: 2019-12-20
Filing date: 2020-12-18
Publication date: 2023-11-21
Anticipated expiration: 2040-12-18
Also published as: WO2021123103A1; CN114901329A; GB2593137A; EP4076589A1; GB2593137B; CN117482333A; GB201919085D0; US20230016544A1; JP2023507477A

Abstract

An appliance (100) for use with an automatic injection device configured to receive a syringe and comprising: a firing assembly (102), the firing assembly (102) comprising a rear portion (108), a plunger rod (110) movable forward relative to the rear portion (108), and a plunger rod driver (112) configured to drive the plunger rod (110) forward relative to the rear portion (108); and an insertion driver (106), the insertion driver (106) configured to drive the syringe forward in an insertion stroke for inserting a needle of the syringe into an injection site; and wherein the firing assembly (102) further comprises a retainer (114) engaged with the plunger rod (110) and/or the rear portion (108) and configured to: preventing forward movement of the plunger rod (110) relative to the rear portion (108) and disengagement from the firing assembly (102) at a point in the insertion stroke.

Description

Syringe appliance

Technical Field

The present invention relates to automatic injection devices and, more particularly, to an appliance for use with an automatic injection device.

Background

An automatic injection device is a device for receiving a syringe and driving a syringe plunger into the barrel of the syringe, typically for drug delivery, without any force applied by the user. Typically, automatic injection devices include a plunger driver, often comprising a spring, arranged to provide a force to drive a syringe plunger into a barrel. The plunger driver is typically activated by operating a release mechanism (e.g., a button) on the automatic injection device or by pressure applied to the injection site via the automatic injection device.

Disclosure of Invention

According to a first aspect of the present invention there is provided an instrument for use with an automatic injection device configured to receive a syringe, the instrument comprising a firing assembly and an insertion driver, the firing assembly comprising: a rear portion, a plunger rod movable forward relative to the rear portion, and a plunger rod driver configured to drive the plunger rod forward relative to the rear portion; the insertion driver is configured to drive the syringe forward in an insertion stroke for inserting a needle of the syringe into an injection site; wherein the firing assembly further comprises a retainer engaged with the plunger rod and/or the rear portion and configured to prevent forward movement of the plunger rod relative to the rear portion and configured to disengage the firing assembly at a point in the insertion stroke.

Optionally, the insertion driver is further configured to drive at least the plunger rod, the plunger rod driver and the rear portion forward in the insertion stroke.

Optionally, the disengagement of the holder is caused by a relative axial movement between the holder and the plunger rod, the plunger rod driver and the rear part.

Optionally, the retainer is axially fixed relative to a housing of the automatic injection device.

Optionally, the plunger rod driver biases the plunger rod forward relative to the rear portion.

Optionally, one of the rear portion and the plunger rod comprises an inclined surface configured to interact with a corresponding feature on the other of the rear portion and the plunger rod under a bias of the plunger rod driver to effect relative rotation between the rear portion and the plunger rod, wherein the retainer is configured to prevent relative rotation between the rear portion and the plunger rod.

Optionally, the retainer comprises a tip configured to abut a surface of the plunger rod to prevent relative rotation between the rear portion and the plunger rod.

Optionally, forward movement of the firing assembly in the insertion stroke causes the nib to not abut a surface of the plunger rod.

Optionally, an axial length of the tip defines a point during the insertion stroke at which the retainer is disengaged from the firing assembly.

Optionally, the point at which the retainer disengages from the firing assembly during the insertion stroke is substantially at the end of the insertion stroke.

According to another aspect of the present invention there is provided an automatic injection device subassembly comprising an implement and a housing, the automatic injection device subassembly comprising a firing assembly and an insertion driver, the firing assembly comprising: a rear portion, a plunger rod movable forward relative to the rear portion, and a plunger rod driver configured to drive the plunger rod forward relative to the rear portion, the firing assembly being insertable into the housing, the insertion driver being configured to drive the syringe forward in an insertion stroke for inserting a needle of the syringe into an injection site, wherein the firing assembly further comprises a retainer engaged with the plunger rod and/or the rear portion, and the retainer is configured to prevent the plunger rod from moving forward relative to the rear portion and configured to disengage the firing assembly at a point in the insertion stroke.

According to another aspect of the present invention, there is provided an instrument for use with an automatic injection device configured to receive a syringe, the instrument comprising a firing assembly comprising: a rear portion; a plunger rod, which is movable forward relative to the rear portion; a plunger rod driver configured to drive the plunger rod forward relative to the rear portion; and a retainer engaged with the plunger rod and/or the rear portion to prevent forward movement of the plunger rod relative to the rear portion, wherein the firing assembly is configured to be inserted into the automatic injection device such that the plunger rod is received within a barrel of the syringe, and wherein the retainer is configured to engage an axial lock for axially securing a position of the retainer relative to the automatic injection device when a front end of the plunger rod is in a particular position relative to a stopper located within the barrel.

Optionally, the instrument further comprises an actuator coupled to the firing assembly and configured to be received in a housing of the automatic injection device to insert the firing assembly into the automatic injection device, wherein the actuator comprises the axial lock.

Optionally, the retainer is configured to engage the axial lock upon relative rotation between the actuator and the retainer.

Optionally, the actuator comprises a plurality of locking features, and wherein relative rotation between the actuator and the retainer causes engagement between a retaining feature of the retainer and one of the plurality of locking features.

Optionally, one of the actuator and the firing assembly includes a ramped surface configured to interact with a corresponding feature on the other of the actuator and the firing assembly to cause relative rotation between the retainer and the actuator.

Optionally, the actuator comprises a sleeve configured to receive the firing assembly therein.

Optionally, the actuator further comprises an end cap configured to abut a surface of the housing to fix an axial position of the actuator relative to the housing.

Optionally, the retainer is configured to engage the axial lock when the end cap abuts a surface of the automatic injection device.

Optionally, the device further comprises an insertion driver configured to drive the syringe, the plunger rod driver and the rear portion forward in an insertion stroke for inserting a needle of the syringe into an injection site.

Optionally, the axial lock is configured to prevent forward movement of the retainer such that forward movement of the syringe, the plunger rod driver and the rear portion forward in the insertion stroke disengages the retainer from the plunger rod and/or the rear portion.

According to another aspect of the present invention there is provided an automatic injection device sub-assembly comprising an appliance according to any one of claims 12 to 22, and further comprising a housing configured to receive the appliance.

According to a further aspect of the present invention there is provided an automatic injection device comprising an appliance according to any one of claims 1 to 10 and claims 12 to 21, and/or an automatic injection device sub-assembly according to claim 11 or 22.

Optionally, the automatic injection device further comprises a syringe comprising a barrel and a stopper located in the barrel.

According to another aspect of the present invention there is provided a method of assembling an appliance for use with an automatic injection device, the method comprising: inserting a firing assembly at least partially into a barrel of a syringe, the firing assembly including a rear portion, a plunger rod movable forward relative to the rear portion, a plunger rod driver configured to drive the plunger rod forward relative to the rear portion, and a retainer engaged with the plunger rod and/or the rear portion to prevent forward movement of the plunger rod relative to the rear portion; and engaging the retainer with an axial lock for axially fixing the position of the retainer relative to the automatic injection device when the front end of the plunger rod is in a specific position relative to a stopper located within the barrel.

Optionally, the instrument may further comprise an actuator coupled to the firing assembly, wherein at least partially inserting the firing assembly into the barrel of the syringe comprises: the actuator is at least partially inserted into a barrel of the syringe.

Optionally, the actuator includes the axial lock, and engaging the retainer with the axial lock includes: causing relative rotation between the actuator and the retainer.

Optionally, wherein one of the actuator and the firing assembly includes a ramped surface configured to interact with a corresponding feature on the other of the actuator and the firing assembly to cause relative rotation between the retainer and the actuator.

Optionally, inserting the actuator into the housing comprises: the actuator is moved forward within the housing until an end cap of the actuator abuts a surface of the housing.

Optionally, the retainer is configured to engage the axial lock when the end cap abuts a surface of the housing.

Drawings

FIG. 1 illustrates a perspective view of an exemplary appliance;

FIG. 2a illustrates an exploded view of an exemplary firing assembly;

FIG. 2b illustrates a perspective view of the exemplary firing assembly of FIG. 2 a;

FIG. 2c illustrates a schematic view of an exemplary firing assembly;

fig. 3 shows a perspective view of an exemplary cartridge;

FIG. 4a is a plan view of an exemplary appliance in a first position, and FIG. 4b is a perspective view of an exemplary appliance in a first position;

FIG. 5a is a plan view of an exemplary appliance in a second position, and FIG. 5b is a perspective view of an exemplary appliance in a second position; and is also provided with

Fig. 6a is a plan view of the exemplary appliance in a third position, and fig. 6b is a perspective view of the exemplary appliance in the third position.

Detailed Description

Generally, disclosed herein are devices for use with automatic injection devices. An example instrument may include a firing assembly configured to be actuated under the force of an insertion driver during an insertion stroke for inserting a needle of an automatic injection device into an injection site. Actuation of the firing assembly may cause release of a plunger rod of the firing assembly to drive a stopper of a syringe within the automatic injection device forward to dispense a substance therefrom. In an exemplary instrument, actuation of the firing assembly may occur substantially at the end of the insertion stroke. In such an arrangement, the user is not required to separately actuate the firing assembly. The user needs to simply activate the device to release the insertion driver, which then automatically activates the firing assembly at a point in the insertion stroke.

An exemplary firing assembly may include a rear portion, a plunger rod, and a plunger rod driver. The plunger rod is movable forward relative to the rear part under the force of the plunger rod driver. In an example arrangement, the firing assembly may include a retainer configured to prevent forward movement of the plunger rod relative to the rear portion when engaged with at least one of the plunger rod and/or the rear portion. Upon disengagement of the holder, the plunger rod may be free to move forward relative to the rear part under the force of the plunger rod driver to dispense the substance from the syringe of the automatic injection device. In such an arrangement, the retainer may be configured to disengage from the plunger rod and/or the rear portion at a point in the insertion stroke, which point may be substantially the end of the insertion stroke.

The disengagement of the holder from the plunger rod and/or the rear part may be caused by a relative axial movement between the holder and the plunger rod and/or the rear part. In an exemplary arrangement, insertion of an instrument into a housing of an automatic injection device during assembly of the automatic injection device may engage a retainer with an axial lock to fix an axial position of the retainer relative to the housing. The plunger rod, the plunger rod driver and the rear part may be configured to move forward in the insertion stroke under the force of the insertion driver. Thus, forward movement of the plunger rod and/or the rear portion under the force of the insertion driver may cause relative axial movement between the holder and the plunger rod and/or the rear portion to disengage the holder.

Throughout the specification, the term "front" includes the end of the automatic injection device from which the medicament is delivered. In other words, the front end of the automatic injection device is the end that is proximal to the injection site (i.e., the needle end) during use. Thus, "forward movement" refers to movement of the implement/component toward the needle end, and "forward end" of the implement/component refers to the end of the implement/component closest to the needle end of the automatic injection device when the implement/assembly is received into the automatic injection device. The term "posterior" or "rearward" refers to away from or away from the injection site during use.

Fig. 1 shows an appliance 100 for use with an automatic injection device. The appliance 100 may be configured to be inserted into a housing of an automatic injection device. The instrument 100 includes a firing assembly 102, an actuator 104, and an insertion drive 106.

FIG. 2a shows an exploded view of the firing assembly 102, and FIG. 2b shows an exemplary firing assembly 102 isolated from the actuator 104 and the insertion drive 106. Firing assembly 102 includes a rear portion 108, a plunger rod 110, a plunger rod driver 112, and a retainer 114. The firing assembly is described below with reference to fig. 2a and 2 b.

In the arrangement shown in fig. 2a and 2b, the plunger rod 110 is movable relative to the rear part 108. The plunger rod 110 is capable of moving forward relative to the rear portion 108. In the exemplary firing assembly 102, the plunger rod driver 112 is configured to drive the plunger rod 110 forward relative to the rear portion 108. The retainer 114 is configured to engage the plunger rod 110 and/or the rear portion 108 to prevent forward movement of the plunger rod 110 relative to the rear portion.

In the exemplary arrangement shown in fig. 2a and 2b, a plunger rod driver 112 is provided between the rear portion 108 and the plunger rod 110. The plunger rod driver 112 may be configured to bias the plunger rod 110 forward relative to the rear portion 108. In the exemplary firing assembly 102 of fig. 2a and 2b, the plunger rod driver 112 comprises a compression spring. In the context of this specification, the term "driver" is used to encompass essentially any component capable of exerting a force on the plunger rod 110. Accordingly, the skilled artisan will appreciate that in alternative arrangements, the plunger rod driver 112 may include alternative biasing members, such as an extension spring or a tension spring.

The retainer 114 may be configured such that engagement with the plunger rod 110 and/or the rear portion 108 prevents axial separation of the plunger rod 110 and the rear portion 108. In such an arrangement, the plunger rod driver 112 may remain in a cocked state or energized state between the rear portion 108 and the plunger rod 110. The plunger rod driver 112 may be configured to bias the plunger rod 110 forward relative to the rear portion 108 when the plunger rod driver 112 is released from the cocked state. In the exemplary arrangement shown in fig. 2a and 2b, the plunger rod driver 112 may be released from the cocked state when the retainer 114 disengages the plunger rod 110 and/or the rear portion 108 to allow the plunger rod 110 to move forward relative to the rear portion 108 under the bias of the plunger rod driver 112.

In the exemplary arrangement shown in fig. 2a and 2b, the plunger rod driver 112 is maintained in a cocked state between the surface of the plunger rod and the reaction surface of the rear part 114. In the exemplary arrangement of fig. 2a and 2b, the plunger rod 110 comprises a bore 120 within which the plunger rod driver 112 is received. The forward end of the plunger rod driver 112 may abut the inner surface of the plunger rod 110. The interior surface of plunger rod 110 may be proximate front end 122 of plunger rod 110. The rearward end of the plunger rod driver 112 may abut the inner surface of the rear portion 108. The inner surface of the rear portion 108 may be proximate the rear end 123 of the rear portion 108.

The rear portion may include a pin 125. The pin 125 may extend axially forward from a rear surface of the rear portion 123 (e.g., an inner surface of the rear portion 108 described above). In the exemplary arrangement shown in fig. 2a and 2b, the plunger rod driver 112 comprises a compression spring. In such an arrangement, the pin 125 may be received within a central bore of the compression spring. The pin 125 may extend along substantially the entire length of the compression spring in its cocked state. The pin 125 may be configured to prevent the compression spring from bending when the compression spring is placed in an armed state and/or to act as a guide when the compression spring is released from the armed state and expands.

As will be described below, in an exemplary arrangement, the rear portion 108 may be axially fixed relative to the housing of the automatic injection device when the firing assembly 102 is fully inserted into the housing. In such an arrangement, when the plunger rod driver 112 is released from the cocked state, the plunger rod 110 is driven forward relative to the rear portion 108 and rearward movement of the rear portion 108 under the force of the plunger rod driver 112 is prevented.

The plunger rod 110 is telescopically received within the rear portion 108. The rear portion 108 may include an inclined surface 124, which inclined surface 124 is configured to interact with a corresponding feature 126 (or plunger rod follower) on the plunger rod 110. The interaction between the inclined surface 124 and the corresponding feature 126 may cause relative rotation between the rear portion 108 and the plunger rod 110. In an exemplary arrangement, the corresponding feature 126 of the plunger rod 110 is configured to travel along the inclined surface 124 of the rear portion 108 to cause the relative rotation. Thus, the angled surface 124 of the rear portion 108 may translate axial force applied to the plunger rod 110 into rotational movement of the plunger rod 110 relative to the rear portion 108. In the exemplary arrangement shown in fig. 2a and 2b, the plunger rod 110 comprises two corresponding features and the rear portion 108 comprises two inclined surfaces. However, those skilled in the art will appreciate that in alternative arrangements, the plunger rod 110 and the rear portion 108 may include substantially any number of corresponding features and sloped surfaces.

In the example shown in fig. 2a and 2b, the corresponding feature 126 of the plunger rod 110 comprises a corresponding inclined surface. However, those skilled in the art will appreciate that in alternative arrangements, the corresponding feature 126 may comprise a peg or a lug, or any other feature capable of interacting with an inclined surface to convert an axial force into a rotational force. Those skilled in the art will further appreciate that in alternative arrangements, the plunger rod 110 may include an inclined surface 124 and the rear portion 108 may include a corresponding feature 126.

In an exemplary arrangement, the plunger rod driver 112 biases the corresponding feature 126 of the plunger rod 110 into engagement with the sloped surface 124 of the rear portion 108.

In the example shown in fig. 2a and 2b, the retainer 114 is configured to prevent forward movement of the plunger rod 110 relative to the rear portion 108. The retainer may be configured to prevent forward movement of the plunger rod 110 relative to the rear portion by preventing separation of the plunger rod 110 and the rear portion 108. Thus, the plunger rod driver 112 remains in a cocked or energized state. In the exemplary arrangement of fig. 2a and 2b, the plunger rod driver 112 is maintained in a cocked state between the inner surface of the plunger rod 110 and the inner surface of the rear portion 108.

In the example shown, the retainer 114 may be configured to prevent forward movement of the plunger rod 110 relative to the rear portion 108 by preventing relative rotation between the plunger rod 110 and the rear portion 108. In such an arrangement, the retainer 114 may be configured to prevent the corresponding feature 126 on the plunger rod 110 from traveling along the sloped surface 124 of the rear portion 108.

The retainer 114 may include at least one nib 130 configured to resist rotation of the plunger rod 110 relative to the rear portion 108. In the exemplary arrangement shown in fig. 2a and 2b, the retainer includes a pair of opposing prongs 130a, 130b, however, those skilled in the art will appreciate that alternative arrangements may include substantially any number of prongs.

Fig. 2c shows a schematic view of the interaction between the tip 130, the plunger rod 110 and the rear part 108 according to the exemplary arrangement of fig. 2a and 2 b. The plunger rod 110 is biased forward (as indicated by arrow F) under the force of the plunger rod driver 112. The corresponding feature 126 (or plunger rod follower) of the plunger rod 110 abuts the inclined surface 124 of the rear portion 108 such that the corresponding feature 126 is biased to travel along the inclined surface 124 of the rear portion 108 under the force F of the plunger rod driver 112. Thus, force F acts to rotate plunger rod 110 in direction D relative to rear portion 108. The corresponding feature 126 of the plunger rod 110 is prevented from moving along the sloped surface 124 of the rear portion by the nib 130.

The nib 130 is configured to abut a surface 132 of the plunger rod 110 and a surface 134 of the rear portion 108, respectively. As can be seen in fig. 2c, the plunger rod driver 112 wants to bias the plunger rod 110 in direction D due to the engagement of the corresponding feature 126 and the inclined surface 124. However, movement of the corresponding feature 126 along the sloped surface 124 in the direction D is prevented by the nib 130. The surface 132 of the plunger rod is pushed towards the tip 130 in direction D under the force of the plunger rod driver 112, however, the engagement of the tip 130 with the surface 134 of the rear portion 108 prevents movement of the plunger rod 110 and the tip 130 in direction D.

In the exemplary arrangement shown in fig. 2a and 2b, the retainer 114 is capable of disengaging the plunger rod 110 and/or the rear portion 108 to allow forward movement of the plunger rod 110 relative to the rear portion 108. In such an arrangement, the retainer 114 can disengage the plunger rod 110 and/or the rear portion 108 upon relative axial movement between the retainer and the plunger rod 110 and/or the rear portion 108 (and, thus, the plunger rod driver 112).

In the exemplary arrangement shown in fig. 2a and 2b, axial movement of the plunger rod 110 and/or the rear portion 108 relative to the holder 114 causes the nib 130 not to abut the surfaces 132, 134 of the plunger rod 110 and the rear portion 108. Those skilled in the art will appreciate that the extent of relative axial movement required to urge the nib 130 out of engagement with the surfaces 132, 134 may be defined by the axial length of the nib 130. Forcing the nib 130 out of engagement with the surfaces 132, 134 may allow relative rotation between the plunger rod 110 and the rear portion 108 and, thus, forward movement of the plunger rod 110 relative to the rear portion 108 under the force of the plunger rod driver 112.

The insertion driver 106 will now be described with reference to fig. 1. The insertion driver 106 may be configured to drive the syringe forward within the automatic injection device during an insertion stroke for inserting the needle of the syringe into the injection site. In the example arrangement shown in fig. 1, the insertion driver 106 may be further configured to drive one or more components of the firing assembly 102 forward during an insertion stroke. In an exemplary arrangement, the one or more components may include at least a rear portion 108, a plunger rod 110, and a plunger rod driver 112.

In the example shown in FIG. 1, the insertion driver 106 is disposed between the actuator 104 and a reaction surface 140 of the firing assembly 102. The insertion driver 106 of fig. 1 includes a compression spring. However, those skilled in the art will appreciate that in alternative arrangements, alternative drivers may be used to apply a forward force on one or more components of the firing assembly 103. For example, the insertion driver 106 may include a tension spring or a tension spring.

In the example arrangement of FIG. 1, the insertion driver 106 is disposed between a reaction surface 140 of the actuator 104 and a surface 142 of the firing assembly 102. As will be described in more detail below, the axial position of the actuator 104 relative to the automatic injection device may be fixed such that release of the insertion driver 106 drives at least the rear portion 108, the plunger rod 110 and the plunger rod driver 112 forward in the insertion stroke without causing the actuator 104 to move rearward.

In the example shown in fig. 1, firing assembly 102 also includes a cartridge (cartridge) 150. The term "cartridge" may encompass any sleeve, collar, or other component capable of receiving a firing assembly. For example, a sleeve, collar, or other component is configured to telescopically receive the firing assembly such that the firing assembly is movable therein.

The cartridge 150 may be configured to receive the firing assembly 102 therein. In the exemplary arrangement of fig. 1, the cartridge 150 telescopically receives the firing assembly 102. The firing assembly 102 may be coupled to the cartridge 150 such that axial movement of the cartridge 150 causes corresponding axial movement of the firing assembly 102. In an exemplary arrangement, the cartridge 150 can include a surface 142. Thus, in an exemplary arrangement, the insertion driver 106 may be disposed between the reaction surface 140 of the actuator and the surface 142 of the cartridge 150. The tube housing 150 is shown separately in fig. 3.

As can be seen in fig. 3, the exemplary cartridge 150 may include a first portion 152 and a second portion 154. However, those skilled in the art will appreciate that in alternative arrangements, the cartridge 150 may comprise a single portion.

In the exemplary arrangement shown in fig. 1, the firing assembly 103 may be coupled to the cartridge 150 by the rear portion 108. The rear portion 108 may include a locking feature configured to engage a corresponding locking feature on the cartridge 150. Accordingly, the insertion driver 106 may be configured to drive one or more components of the firing assembly 103 forward. In an exemplary arrangement, one or more components of the firing assembly include at least a rear portion 108, a plunger rod 110, and a plunger rod driver 112.

In alternative arrangements, the rear portion 108 may include one or more features of the cartridge 150. In such an arrangement, there may be no separate cartridge component.

In an exemplary arrangement, the retainer 114 may be configured to engage an axial lock for axially fixing the position of the retainer 114 relative to the housing of the automatic injection device. The retainer 114 may include at least one retention feature 160 configured to engage an axial lock. In the example shown, the retention feature 160 comprises a radially extending protrusion, however, it will be apparent to those skilled in the art that alternative features may be used to engage the axial lock.

In the exemplary appliance 100 shown in fig. 1, the actuator 104 includes an axial lock 162. In such examples, engagement of the retention feature 160 with the axial lock axially fixes the position of the retainer 114 relative to the actuator 104. As described in more detail below, the position of the actuator 104 may be axially fixed relative to the housing of the automatic injection device, and thus, the engagement of the retention feature 160 with the axial lock 162 axially fixes the position of the retainer 114 relative to the housing of the automatic injection device.

The axial lock 162 may include a plurality of locking features. The plurality of locking features may be axially spaced along at least a portion of the length of the actuator 104. In the example actuator 104 shown in fig. 1, the plurality of locking features are axially spaced apart over substantially the entire length of the actuator 104.

The retention feature 160 of the retainer 114 may be configured to engage one of a plurality of locking features of the axial lock 162 to fix the position of the retainer 114 relative to the actuator 104. Thus, as will be apparent to those skilled in the art, the retainer 114 can be secured to the actuator 104 at a number of different points along the length of the actuator. While the exemplary locking feature in the arrangement shown in fig. 1 provides a plurality of discrete locations along the length of the actuator 104 to which the retainer 114 may be secured, a continuous locking arrangement may alternatively be provided such that the retainer 114 may be secured to the actuator 102 at substantially any point along the length of the actuator 104.

The retainer 114 may be configured to engage the axial lock 162 upon relative rotation between the actuator 104 and the retainer 114. In such an arrangement, relative rotation between the actuator 104 and the retainer 114 may cause engagement of the retention feature 160 of the retainer 114 with one of the plurality of locking features of the axial lock 162.

In the example actuator 104, the plurality of locking features of the axial lock 162 include teeth. The teeth may be arranged in a linear track extending along at least a portion of the length of the actuator 104. In the example arrangement of fig. 1, the teeth may be located on an inner surface of the actuator 104. The teeth may be rearwardly sloped and configured to engage corresponding sloped surfaces of the retention features 160 on the retainer 114.

The firing assembly 102 may be coupled to an actuator 104. In the exemplary arrangement shown in FIG. 1, the firing assembly 102 is telescopically received within an actuator 104. The actuator may include a ramped surface 168, the ramped surface 168 configured to interact with a corresponding feature on the firing assembly 102 to cause relative rotation between the retainer 114 and the actuator 104 to engage the retainer with the axial lock 162.

In the exemplary arrangement shown in fig. 1, the cartridge 150 includes corresponding features 170 (or cartridge follower) visible in fig. 3. As described above, the rear portion 108, the plunger rod 110, the plunger rod driver 112 and the retainer 114 are coupled to the cartridge 150. Thus, rotation of the cartridge 150 relative to the actuator 104 causes rotation of the rear portion 108, the plunger rod 110, the plunger rod driver 112 and the retainer 114 relative to the actuator 104.

In the exemplary arrangement of fig. 1, the actuator 104 includes a sleeve 178. The actuator 104 may also include an end cap 180. The end cap 180 may be configured to abut a rear surface of a housing of an automatic injection device when the device 100 is fully inserted into the housing of the automatic injection device.

In the exemplary arrangement of fig. 1, the sleeve 178 extends from an end cap 180. The barrel 178 may be configured to receive the firing assembly 102 therein. In the arrangement of fig. 1, the sleeve 178 is configured to receive the cartridge 150 therein. In such an arrangement, the sleeve 178 may include the ramped surface 168.

The actuator 104 may also include a drive rail 182. The drive rail 182 may include an axial section to allow the corresponding feature 170 of the cartridge 150 to move axially therein. The corresponding feature 170 of the cartridge may be configured to travel along the drive track to allow relative axial movement between the actuator 104 and the drive track 182 under the bias of the insertion drive 106.

The operation of the appliance 100 will now be described with reference to fig. 4 a-6 b.

Fig. 4a and 4b show the appliance 100 in an initial position. In the initial position, the retainer 114 engages the plunger rod 110 and/or the rear portion 108 to prevent forward movement of the plunger rod 110 relative to the rear portion 108, as described above. At this point, in an exemplary arrangement, the rear portion 108 may be disengaged from the cartridge 150 such that the rear portion 108, the plunger rod 110, the plunger rod driver 112, and the retainer 114 are able to move axially relative to the cartridge 150. In an alternative arrangement, the rear portion 108 may be coupled to the cartridge 150 in an initial position.

The corresponding feature 170 of the cartridge 150 may engage the ramped surface 168 of the actuator 104. As shown in fig. 4b, the corresponding feature 170 may be located at the foremost point of the ramp surface 168.

The firing assembly 102 may be inserted into a housing of an automatic injection device. The automatic injection device housing may already receive a syringe comprising a barrel and a stopper. In an exemplary automatic injection device, the injector may be received and held near the front end of the automatic injection device housing.

The firing assembly 102 may be moved forward within the housing of the automatic injection device such that the plunger rod 110 is received within the barrel of a syringe located within the housing of the automatic injection device. In an exemplary arrangement, an axial force may be applied to the actuator 104 to insert the firing assembly 102 into the housing of the automatic injection device.

At a point during forward movement of the firing assembly 102 within the housing, the front end 122 of the plunger rod 110 may contact a stopper located within the barrel of a syringe within the automatic injection device. It will be appreciated by those skilled in the art that the syringe may be a pre-filled syringe and that in such an arrangement the point at which the plunger rod 110 contacts the stopper will depend on the fill volume of the pre-filled syringe.

Once the plunger rod 110 contacts the stopper, further forward movement of the rear portion 108, plunger rod 110, plunger rod driver 112 and retainer 114 is prevented. This is because, as described above, the rear portion 108 and the plunger rod driver 112 are coupled to the plunger rod 110 by the retainer 114. Thus, further force applied to the actuator 104 causes axial movement between the cartridge 150 and at least the rear portion 108, the plunger rod 110, the plunger rod driver 112 and the retainer 114.

In the exemplary arrangement of fig. 4a and 4b, further forward movement of the actuator 104 under axial force causes further forward movement of the cartridge 150, as the actuator 104 and cartridge 150 are coupled. Accordingly, the cartridge 150 continues to move forward within the housing while the rearward portion 108, the plunger rod 110, the plunger rod driver 112 and the retainer 114 remain in substantially the same axial position relative to the housing. Thus, more of the length of plunger rod 110 is received within cartridge 150 and the extent to which front end 122 of plunger rod 110 extends beyond the front end of cartridge 150 begins to decrease.

At a point during insertion, the cartridge 150 may be prevented from moving further forward within the housing. This may be due to, for example, the cartridge 150 abutting the syringe. In alternative arrangements, the cartridge 150 may engage alternative components (or features on the auto-injector housing) to prevent further forward movement.

When forward movement of the cartridge 150 is prevented, continued application of axial force on the actuator 104 may cause relative rotation between the cartridge 150 and the actuator 104. In the example arrangement of fig. 4a and 4b, the corresponding feature 170 of the cartridge 150 traveling along the ramp surface 168 of the actuator 104 may cause relative rotation.

In an exemplary arrangement, rotation of the cartridge 150 relative to the actuator 104 may couple the cartridge 150 to the rear portion 108. The relative rotation between the cartridge 150 and the actuator 104 may cause relative rotation between the cartridge 150 and the rear portion 108 (which is substantially rotationally stationary when disengaged from the cartridge 150). In such an arrangement, upon relative rotation of the cartridge 150 and the rear portion 108, the locking features of the rear portion 108 may engage corresponding locking features on the cartridge 150. As described above, in an alternative arrangement, the rear portion 108 may already be coupled to the cartridge 150, in which case rotation of the cartridge 150 may cause corresponding rotation of the rear portion 108.

Further rotation of the cartridge 150 relative to the actuator 104 after the cartridge 150 and the rear portion 108 have been coupled causes relative rotation of the retainer 114 relative to the actuator 104. Relative rotation between the retainer 114 and the actuator 104 may cause the retainer 114 to engage the axial lock 162. In the example arrangement of fig. 4 a-4 b, relative rotation between the retainer 114 and the actuator causes the retention feature 160 of the retainer 114 to engage one of a plurality of locking features of the axial lock 162 of the actuator 104. This is shown in fig. 5a and 5 b.

Engagement of the retainer 114 with the axial lock 162 may axially fix the position of the retainer 114 relative to the automatic injection device. In an exemplary arrangement, the retainer 114 may be configured to engage the axial lock 162 when the appliance 100 has been fully inserted into the housing of an automatic injection device. This may be when the end cap 180 of the actuator 104 abuts a surface of the housing. Abutment between the end cap 180 and the surface of the housing may fix the axial position of the actuator 104 relative to the housing. As described above, because the engagement between the retainer 114 and the axial lock 162 secures the axial position of the retainer 114 relative to the actuator 104, the axial position of the retainer 114 relative to the housing may be fixed when the appliance is fully inserted within the housing.

It will be apparent to those skilled in the art that the retainer 114 engages the axial lock 162 when the front end 122 of the plunger rod 110 is in a particular position relative to the stopper within the barrel of the syringe. In some arrangements, this particular location may correspond to the front end 112 of the plunger rod 110 contacting the stopper. In an alternative arrangement, a space may be created between the stopper and the front end 122 of the plunger rod 110 during insertion of the device 100. For example, the firing assembly 102 may be moved rearward during insertion of the firing assembly into a housing of an automatic injection device. In such an arrangement, the specific position may correspond to a specific spacing between the stopper and the front end of the plunger rod 110.

Fig. 5a and 5b show the appliance at the point where the retainer 114 engages the axial lock 162. In the exemplary arrangement, at this point, the travel of the corresponding portion 170 along the ramp surface 168 of the actuator 104 has been completed and the corresponding feature 170 of the cartridge 150 has entered the drive track 182. As shown in fig. 5a and 5b, the corresponding feature 170 may be positioned at the last point of the drive track 182. The corresponding feature 170 may be configured to travel forward within the drive rail 182 under the force of an inserted driver 106, as described below.

Upon user actuation of the automatic injection device, the insertion driver 106 may drive one or more components of the firing assembly 102 forward during an insertion stroke. In the exemplary arrangement shown in fig. 4 a-5 b, the insertion driver biases the cartridge 150 forward. This causes the corresponding feature 170 to travel along the drive rail 182. As described above, since the axial position of the actuator 104 is fixed relative to the housing, the actuator 104 is prevented from moving rearward under the bias of the insertion driver.

As described above, the rear portion 108 is coupled to the cartridge 150. Thus, forward movement of the cartridge 150 causes forward movement of the rear portion 108. This in turn causes forward movement 112 of the plunger rod 110 and plunger rod driver. Because the axial position of the retainer 114 is fixed relative to the housing, the retainer does not move forward under the bias of the insertion driver 106. Thus, the rear portion 108, the plunger rod 110 and the plunger rod driver 112 move axially relative to the holder 114 during the insertion stroke.

In the exemplary appliance 100, relative axial movement disengages the retainer 114 from the plunger rod 110 and the rear portion 108. In the example shown, the relative axial movement causes the tip 130 of the retainer 114 to not engage the plunger rod 110 and the rear portion 108. This is shown in fig. 6a and 6 b.

At a point in the insertion stroke, the nib 130 is urged completely out of engagement with the plunger rod 110 and the rear portion 108. That is, the tip 130 may not abut the surface 132 of the plunger rod 110 and the surface 134 of the rear portion 108, respectively. As described above, the point at which the axial length of the nib 130 causes the nib 130 to completely disengage from the plunger rod 110 and rear portion 108 during the insertion stroke may be defined. This point may be substantially at the end of the insertion stroke. The end of the insertion stroke may be the point at which the needle of the syringe of the automatic injection device is fully inserted into the injection site. At the end of the insertion stroke, in an exemplary arrangement, the cartridge 150 may have completed its forward movement, and the corresponding feature 170 of the cartridge 150 may be located at the forward-most point of the driver track 182.

Disengagement of the retainer 114 from the plunger rod 110 and the rear portion 108 allows the plunger rod 110 to move forward relative to the rear portion 108 under the force of the plunger rod driver 112. In the exemplary arrangement shown in fig. 4 a-6 b, the disengagement holder 114 allows the plunger rod 110 to rotate relative to the rear portion 108. This is because the prongs 130 of the retainer 114 no longer prevent the corresponding features 126 on the plunger rod 110 from traveling along the angled surface 124 of the rear portion 108 under the bias of the plunger rod driver 112. Accordingly, the corresponding feature 126 on the plunger rod 110 travels along the inclined surface 124 of the rear portion 108.

Once the corresponding feature 126 on the plunger rod 110 completes its travel along the inclined surface 124 of the rear portion 108, the plunger rod 110 is free to travel axially forward relative to the rear portion 108 under the force of the plunger rod driver 112. Axial forward travel of plunger rod 110 relative to rear portion 108 may cause plunger rod 110 to drive a stopper of a syringe within a barrel to dispense the substance contained therein.

It should be noted that many of the features of the exemplary appliances described above, as well as the features shown in the figures, may be included in other exemplary appliances. In this way, the different figures are not necessarily to be regarded as separate embodiments, and features from one figure may be transferred to an appliance in another figure. Other appliances and their features will be apparent to those skilled in the art without departing from the scope of the appended claims.

Claims

1. An appliance for use with an automatic injection device configured to receive a syringe, the appliance comprising:

a firing assembly including a rear portion, a plunger rod movable forward relative to the rear portion, and a plunger rod driver configured to drive the plunger rod forward relative to the rear portion;

An insertion driver configured to drive the syringe, the plunger rod driver and the rear portion forward in an insertion stroke for inserting a needle of the syringe into an injection site; and is also provided with

Wherein the firing assembly further comprises a retainer engaged with the plunger rod and/or the rear portion and configured to prevent forward movement of the plunger rod relative to the rear portion by preventing relative rotation between the plunger rod and the rear portion, and

wherein the holder is axially fixed relative to the housing of the automatic injection device such that forward movement of the plunger rod, the plunger rod driver and the rear part in an insertion stroke causes relative axial movement between the holder and the plunger rod, the plunger rod driver and the rear part to disengage the holder from the plunger rod and/or the rear part in the insertion stroke.

2. The appliance of claim 1, wherein the plunger rod driver biases the plunger rod forward relative to the rear portion.

3. The appliance of claim 2, wherein one of the rear portion and the plunger rod includes an inclined surface configured to interact with a corresponding feature on the other of the rear portion and the plunger rod under a bias of the plunger rod driver to effect relative rotation between the rear portion and the plunger rod, and

wherein the retainer is configured to prevent relative rotation between the rear portion and the plunger rod.

4. The appliance of claim 2, wherein the retainer includes a tip configured to abut a surface of the plunger rod to prevent relative rotation between the rear portion and the plunger rod.

5. The instrument of claim 4, wherein forward movement of the firing assembly in the insertion stroke urges the nib out of abutment with a surface of the plunger rod.

6. The instrument of claim 4, wherein an axial length of the prong defines a point during the insertion stroke at which the retainer disengages from the firing assembly.

7. The instrument of claim 1, wherein a point at which the retainer disengages from the firing assembly during the insertion stroke is substantially at the end of the insertion stroke.

8. An automatic injection device subassembly comprising an appliance and a housing, the automatic injection device subassembly comprising:

a firing assembly including a rear portion, a plunger rod movable forward relative to the rear portion, and a plunger rod driver configured to drive the plunger rod forward relative to the rear portion, the firing assembly being insertable within the housing;

Wherein the firing assembly further comprises a retainer engaged with the plunger rod and/or the rear portion and configured to prevent forward movement of the plunger rod relative to the rear portion by preventing relative rotation between the plunger rod (110) and the rear portion, and

wherein the holder is axially fixed relative to the housing of the automatic injection device and forward movement of the plunger rod, the plunger rod driver and the rear part in an insertion stroke causes relative axial movement between the holder and the plunger rod, the plunger rod driver and the rear part to disengage the holder from the plunger rod and/or the rear part in the insertion stroke.

9. An automatic injection device comprising an appliance according to any one of claims 1 to 7, and/or an automatic injection device subassembly according to claim 8.

10. The automatic injection device of claim 9, further comprising a syringe comprising a barrel and a stopper located in the barrel.